Lift truck



Sept. 16, 1952 a. BEVAN 1 LIFT TRUCK Filed May 12, 194? :2Sl-lEETS-SHLET 1 fla 2 SHEETS-SHEET 2 G. BEVAN LIFT TRUCK Sept. 16, 1952Flled May 12 1947 Patented Sept. 16

4* UNITED STATES PATENT E.

LIFT TRUCK:

George Bevan, Norfolk, Va., assignor to Freight Handling Corporation, acorporation of Vii Application May 12,1947, Serial no. 747,3sr ,4oiaims. (01. 214- 4 13) The present invention relates to lift trucks andparticularly to mobile trucks of, the so called forklift type in whichthe platform upon which the load to" be transported is placed has :afork-like appearance owing to the fact that it comprises a plurality ofelongated parallel members extending horizontally from a supportingbase, these members generally tapering outward- 1y from'the base andthus resembling tines.

Many lift trucks of this type are now in use'for' :1

the transportation of goods through relatively short distances,particularly from place to place within. ,afactory building, formovement of freight from factories into freightcars or from freight carsinto warehouses, and elsewhere. The loads which these trucks are calledupon to handle vary greatly in character. Raw materials in bales andmaterials in self-supporting'contai'ners, such, as wooden boxes, must,of course, be frequently and likewise granular and pulverulent materialsin paper or cloth sacks, these envelopes being non-self-supporting andbeing readily broken or torn. Thus the truck must be of such characteras toh'ave the capacity to rea ceive,'sa'fely transport, and deliversacks of flour as well" aslcontainers which" will not break even when'subjectedto rough handling.

Certain commodities may be placed, for the purpose of transportation.and ultimate delivery, directly upon"th e"tines or elongated'loadsuppbrting' elements of the conventional fork lift truck. Hogsh'ea'dsoff'tob'a'cco and large bales and boxesof'othergoods' may with advantagebe handled in this manner. Other commodities,

such for instance as sacks of granular orpulverulent. material, may betransported with greater .safetyupon continuous flat platforms whichprovide uniform support. To provide such support- :ingsur'faces it hastherefore been conventional practice for those employing lift trucks inthe transportation, of goods in sacks or bags'to' em ploy what are knownas pallets. A pallet comprises aload'supporting floor adapted toreceive,

fcr'inst'ance, from three to'six flour sacks formto' thirty such sacks,together with means to space this lead carrying floor a short distanceing a bottomlayer, with others piled thereon in layerformation'to form astack of from fifteen fromthe ground/This spacing of 'the'palletfloorwpermits the tines of a fork lift truck to be moved into positionunder the pallet floor so that the pallet may beengaged, raised, andtransported, together with its superposed load.. The

pallet, lat the'p'oint of loaddischarge, is generally g lowered by thefork lift onto a supporting surpallet'to the loadcarrying portion of afork' ty'pe goods; against movement while the supporting facefstillcarrying its previously placed load, andmay be lost to its owner,particularly if goods in sacks or bags are being loaded into a freightcar for transportation to a distant point. T prevent loss of pallets inthis manner it has been proposed that the lift truck beprovided with apusher by means of which a load may be held stationary as the truck isretracted and that the pallet'and lift a truck be providedlwith mutuallyinterlocking means to insure that the pallet will not be sep- I aratedfrom the lift truck but will simply be withdrawn from beneath the load.1

In accordance with the present invention a load supporting pallet of.novel character is provided, this'being substituted for the usualpallet having spaced upper and lower floors. Improved means are providedfor detachably securing this lift truck. As a feature of this part ofmyinvention, the means for securing the pallet to the, fork truckarepreferably formed so that they Y are" actuated into and out of securingrelation" merely through manipulation of the truck bodily relatively tothe pallet.

'As a further feature of my invention the load supporting pallet takesthe form of a steel plate of desired configuration, and this steelplate. may have legsorf casters thereunder whereby one edge may besupportedseveral inches above a' fioor while the other edge is againstthe floor. Thus, this pallet if placed upon a horizontal surface willassume an inclined positionunless that edge which is normally againstthe surface is supported upon blocks or by other members. It is thefunction of the legs or casters to support one edgeof the pallet at sucha height that the usual forks of a lift truck may readily be in! sertedbeneath the pallet and to permit that manipulation between the truck andpane-trequiredto engage and'disengage the truck and pallet. J

As previously stated, the improved 'loadsupporting pallet i to bepermanently retained at one location and, is preferably held againstdischarge'with its load when the pusher of the associated truck isoperated to .hold apile of pallet is being withdrawn-from beneath thepile. For that reason a special means isprovided for detachably securingthe palletto the elevatingplatform or forks of the truck. This meanspermits the pallet to be readily securedin operative I position and tobe as readily detached, while at the same time is of such character astorequire load, or deposited upon a 3 no modification or alteration inthe structure of the truck itself, which is important. Thus I prefer tsecure detachable the pallet in position to rest upon the forks so thatthe weight of the pallet and its load is transmitted to the forks in theusual manner and I provide, as a securing means, one or more membersthat may be designated attachment members, extending between theelevating platform of the truck and the pallet. By providing means suchas described that may be readily added to a lift truck not intended forsuch operation, the operator of a lift truck can convert the truckquickly and easily, and without the use of securing bolts, or withoutmodifying the structure of the truck in any way, for the transportationof goods of widely different characteristics. It will be appreciated byon skilled in the art that, without departure from the invention,various types of devices for detachably connecting the continuoussurface type of load carrying platform to the lift truck may be devised,although that form to which brief reference has been made, and whichwill hereinafter be described in detail, is preferred.

The improved pallet is preferably fabricated of metal and may be quitethin, whereas the con: ventional pallet has a thickness of five or sixinches. When a conventional pallet of five or six inches in thickness iswithdrawn from beneath a pile of goods, such goods necessarily drop thisdistance of five or six inches onto a supporting floor, or onto a pilewhich has been'previously deposited, causing bags to burst as'they,

pass over the edge of the pallet and also causing the bags or cartons tolose pile formation. When myimproved skid is employed no such dropoccurs upon discharge of goods and all breakage and loss of pileformation is avoided.

The novel pallet furthermore makes possible the practice of an improvedmethod which results in the realization of substantial economies in theloading and transportation of goods. It also becomes possible to fullyload freight cars without additional labor. The use of large numbers ofpallets is avoided, the improvement making it possible to transfer agiven quantity of goods by means of a lift truck 'and' several pallets,and with the expenditure of a relatively small amount of manual laborWhereas, when conventional palletsare employed, a substantial number arerequired and'the amount of labor requiredsubstantially increased.Numerous other advantages will be apparent.

In the accompanying drawings:

Figure l is a perspective view of the forward portion of a lift truck ofthe fork type, showing the novel pallet in chain lines and the elementsfor detachably connecting this pallet to the truck in full lines;

Figure 2 is a section on line 22 of Figure 1;

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a perspective view of one of the attachment elements;

Figure 5 is a similar view of a modified form of attachment element;

Figure 6 is a partial section taken on line 6.8 of Figure 2;

Figure 7 is a section on line T-l of Figure 6 Figure 8 is a perspectiveview of a portion 01' the underside of my pallet, showing an attachedhook member which forms a portion of the means for separably connectingthis pallet to the truck Figure 9 shows in side elevation one of theelongated tines of the fork lift, showing also, in process of assemblytherewith, one of the members by means of which the separable connectionof the pallet to the truck may be effected;

Figure 10 is a section on line Ill-i 0 of Figure 9;

Figure 11 shows in side elevation a pallet resting with one end on afloor or base while the other end is supported by wood blocks, a portionof the front end of a conventional fork lift truck being illustrated,with the tines of the fork under the platform;

Figure 12 is a view showing the elevating platform of the truck in ahigher position, the load carried by the platform being supporteddirectly above a similar load and ready to be discharged; and

Figure 13 is a view of the parts of Fig. 12 with the pusher of thetruck, actuated and the truck with its attached pallet simultaneouslyretracted toeflect the discharge of the load from the pallet upon thetop of a previously deposited load.

As previously explained, the invention is primarily concerned withtrucks of the fork lift type. Such trucks are well known and are incommon use and, inasmuch as the details of construction of the truckitself are unimportant insofar as the present invention is concerned,these details are not illustrated and will not be described.

In the rather diagrammatic Figures 11, 12 and 13 a portion of the truckframe'is indicated at F, one of the front wheels at W, the mast at M,

pusher frame actuating mechanismH." The mast f M is provided, adjacentits'lower end, with at tached hook members oneof which is indicated at It e e mbe ng and b n s bported by a horizontally extending rod llcarried by the truck frame, The mast may be rocked about rod ll througha limited angle, either forwardly from the vertical position 'in' whichit is shown in Figure 11 to an inclined position such as that of Figure12, or rearwardly through a small angle, as desired, and held in anysuch position to which it maybe moved, by any suitable mechanism. ThecarriageC is supported for movement vertically along the mast and somesuitable means for. accomplishing this will be utilized. Qne mechanismfor effecting tilting of the mast and vertical reciprocation of thecarriage C is, for instance, shown in Patent 2299,44,,

issued to E. W. Weaver. Any other such means concerned.

The means H for advancing and retracting the pusher frame P may consistprincipaily of two cylinders l2, secured to Opposite sides of the car;riage C respectively, each having a spring retracted telescopic pistonl3 upon the outer ends of which the pusher frame P is mounted. A conduitfor conducting fluid under pressure to the cylinder shown is indicatedat I4 and it will be understood that by the use of known devices theoperator may control the flow of fluid under pressure to and away fromthe cylinder and hence the operation of the hydraulic means H and themovements of the pusher frame F. l

The forks or tines l5 selected for illustration include two or more (inthis case four) generally parallel horizontally extending outwardlytapering elements, the heavier ends of these elements being suitablyattached in a rigid manner to the carriage or elevator C so that thetines together constitute a generally horizontally disposed loadsupporting means. which may be liftedv and with the truck. As previouslyexplained, the

forks iii are highly useful in the .transportation of certain types ofloads, without the application of a pallet, and are also well suited forengaging, lifting and transporting the conventional pallet.

The present invention contemplates the provision of a pallet generallyindicated at S in the drawings, and which is preferably fabricated ofmetal and in plate form, relatively thin but substantially inflexiblewhen. loaded. It is rectangular and is provided at two adjacent cornerswith legs or supports, such as indicated at I6, solid legs being used ifdesired, but these supports preferably comprisingcastors. The nature ofthe supports is not important exceptthat they should function toallowthe forks to moveunder the floor of the pallet when the palletrests with one end against theground and withiits other end raised bythe supports. In Figure '11 the load carrying forks l5 of the truck areshown inserted under the platform, the end thereof not provided withpermanent supports being mounted upon supporting'blocks B so that theplatform is substantiallyhorizontal. This holding of the pallet floorhorizontal is helpful in the loading thereof but is not essential. It iswell to understand also that the supports l6 may be entirely eliminatedand the pallet floor mounted on blocksthereby to permit entry thereunderof the truck forks.

Intermediate the castors i6, and Welded or otherwise rigidly attached tothe pallet, is an L-' shaped catch I8 which projects downwardly (shownupside down in Fig, 8) and has area-rwardly projecting terminal endportion, this catch comprising one element of a means for separably'connecting the 'pallet to the truck. The pallet is preferably notdirectly attached to any portion of the truck but to an intermediatemeans comprising two atachment members 20, one of whichis shown in itsentirety in Figure 4 of the drawings.

To those skilled in the arteach member will appear to resemble what isknown as an extension fork, adapted to be slipped onto or off.

of a fork or tine 15 at will. and which, when positioned as shown inFigures 1 and 2, is locked to the tine. Actually, the functioning partsof members 20', to be set forth below, may be made integral with forksl5 and said attachments discarded. Locking and unlocking of members 20to the forks is effected without the aid of tools or separate securingdevices. Thus the flat plate with ears 200 which are connected by across bar 22. The space defined by this cross bar 22, the adjacentparallel end edge of the plate, and the flanges 20a and 20b is a tinereceiving space,

shown most clearly in Figure 9. Assembly of member 20 with element I5 isreadily effected by inclining the member 20 as shown in Figures 9 and10, advancing it axially of element l 5 so that the free end of theelement passes through the aperture provided for its reception, andthereafter moving member 20 longitudinally of element l5 until itsleading end has been advanced as far as maybe, whereupon it is loweredso as to lie directiy upon the uppersurface of the member 15 below it,the cross or looking bar 22 passing.

around, in such movement, the curved end of thetine I5 to a position inrear ofthe vertically extending continuation of .this element, which'isindicated at 150. in Figure 2. Attached. flanges 20d abut, when. member20 is so positioned, against a portion l'lb ofthe carriage so that thismember is eifectivelylocked against longitudinal It is clear that, afterassembly of member 20 with a supporting tine in the manner I movement;

just described, this'member cannot move unless by reversing the processof assembly, i. e. tilting it to the position shown in Figure 9 andsliding; it outwardly along thetine and really is an inte gral part ofthe tinefor all purposes.

I Two such members 20 are preferably provided, 1

20c, which edges are in alignment when the two members are fullypositioned as shown in Figure 1. These two edges or shoulders 20etogether.

comprise one portion of the separable connection between pallet S andthe truck, the other portion being the hook l8.

-When the forks l5 and added members 20 are inserted beneath a loadedpallet S, and the pallet is'lifted, thehook member [8 will not becaused, by such simple lifting movement, to actually engage the edgesZoe. However, should there be any forward movement of the pallet uponthe tines I5 as the truck is'manipulated, the hook member will, afterashort forward travel of'the pallet,

engage the edges 20c as seen in Fig. 7, thus preventing further travelof the pallet and its load off the fork lift. When a load is to bedischarged and the pusher P is actuated while the truck is retracted thepallet S, if its hook I8 is still spaced from edges 206, will of courseslideforwardly with the moving load until'the hook 18 engages edges211e, further movement of the pallet upon its support being thenprevented so that the palletv may be withdrawn with the forks frombeneaththe load which it ha'sbeen supporting. Because of the factthatthe hook l8; engages the undersides as well as the'edges of members20 the ML let is prevented also from tilting as the load passes over itsforward edge, '1. e. the edge thereof remote from the hook.

Disengagement of the pallet may be readily ef-' fected either byloweringthe pallet to the ground and then slightly advancing the forks,further lowering and then retracting the fork lift, or by rearwardlytilting the mast and thus causing the pallet to slide toward the truckbody. .This last ment members may be employed, if desired. In

any event the means for detachably securing the pallet to the truck mustbe so formed that the pallet will not only be restrained from slidingtoo far forwardly during an unloading operation but will alsoeffectively prevent tilting of-the .pal-

..-lettabout"the; ends: of. the tines l operation.

Thenovel.mechanismso far described may be. utilized whether: or..not.the. truck is equipped with a;.pushing element such as: illustrated inFor the purpose of. mostv conveniently unloading such'a cargo from aboxcanandstoringit 1113a, warehouse a truck and three pallets can be:used: with great economyas compared with unloading methods now commonlypracticed;

Incarrying -out such unloading operation-one of the -load supportingpallets would be placed adjacent the, door of the car to be unloaded,the two legs of this pallet resting directly upon the; car bottom andthe opposite end being supported upon blocks, for instance wooden blocksone of which is indicated at B in Figure 11', so that the pallet floorwill be disposed horizontally; Actually, the pallet S could be merely aplate equipped with a'hook l8 and supported entirely 'by' blocks. Thesupports or legs are really important however to allow the .-forks to bedisengagedcfromv the hook 18 by the mere manipulation of the forks. Fourmen will then pile a predetermined number. of sacks upon the pallet,such a pile of sacks being illustratedin'Figure 11. This can be readilyaccomplished. The lift truck would then ad- Vance; the fork liftplatform F inserted under the pallet, as illustrated inFigurell, andthecarriage C elevated so that the fork lift with its superposed loadwill be lifted. The truck will then be operated to transport the load tothe storage area. At the point of load discharge: the. operator willcause the mast of the truck to tilt forwardly to a position such as thatin which it is illustrated in Figure '12, thecarriage and fork liftplatform likewise being tilted. forward as shown. If the load is to bedeposited directly upon the r'loor-the tilting operation will bring theforward edge of the'pallet S into contact with the floor, thecarriageCoccupying such position that tilting to an angle of 2 or 3 orthereabouts will'have this result. The operator would then cause thecarriage C 'to move upwardly for the fraction of an inch, for instanceabout a quarter of an inch, thus causing the forward edge of thepalletto be elevated above the fioor-that-amount.

The hydraulic mechanism H is-then energized tocause the pusher frame Pto move forwardly and, simultaneously, the truck is. backedaway. Thepallet. S is thus withdrawn from beneaththe pile of sacks which'a're'held'agains't lateral movement b'y'the pusher element P. As the'pall'etS is withdrawn from beneath the sacks comprising the pile, these sackspass over the forward'bew el'ed edge of-the pallet and drop-to thefloor. The drop-is so slight, however, that there is no break-- age ofany'sackas it passesover theedge of the pallet and'there'is,furthermore,-no such relative movement between the sacks as to causethepile to lose formation. The entire'pile will be delivered intact "andintight pile formationupon the. selected space, without possibilityofbreakage or disruption of any sack.

Should one load already have been deposited on this selected storagearea as'in-Fig. 12, and itbedesired to deposit. a second load on topof'known methods.

therflrst, the procedure will be the same.

in that; the pallet-S and theload carried therebywi1l;beelevatedby'moving the supporting; carriage C upwardly,-forinstance to the position shown. in Figures. 12 andlS. The unloadingop erationswill take. place, however, just as before... thetruck beingbacked away whilethe pusher perating mechanism is actuated in suchmanner as to'hold the load stationary. If desired a third load. may bedeposited in this manner upon the,

top of. the second and the resulting pile will be stable, theindividualzincrements depositedhaving been. maintained in tight pileformation be-- cause' each.was.made.to drop an extremely'in.

consequential distances After. each: load .is deposited the .lift truckwill return :to' the; box car, the pallet being preferably releasedwhile the. truck is on thisreturn movement, the operator: tilting themast. backwardly so: that; .the. pallet; slides toward the truck .untilthehook l8 disengages' the catch members 208..

When the truck' arrives at the loading stationtherefore, the 'pallet maybe readily deposited upon thefloor by simply lowering the carriage Cuntil the. palletmakes, contact with thefloor, the

fork lift being. then retracted as legs or supports Also; where otherengaging means are used, it

may be desired to. remove-the pallet manually and legsmaybe dispensedwith, .the pallet being entirely supported byblocks to allow the forkstoenter: thereunder. The truck will then 'be moved to pickup a palletwhich has previously been loaded and will carry this loaded pallet tothe.

ischarge area and eifect the discharge of the sacks. .therefromdn themanner previously de scribed; The sacks are'piled one upon another andthe use of conventional pallets is wholly avoided. Not only is there asubstantial saving realized by reason of the fact that the use ofconventional pallets is avoided but there is also realized-a substantialsaving in labor even though as many men are required in an'unloadingoperation effected by-means of a truck equipped with the novel mechanismdescribed-as are customarily used when the unloading operation iseffected 'bymeans I of the conventional pallet. It isactually found thatthe labor costs may be reduced by about 15%, in .the unloading of'a carcontaininga-specified number of sacks, this sav-- stead of a largenumber of pallets, say- 40 pallets in the caseof a car of normalcapacity.

When flour in sacks is to be loaded into abox car, instead of beingremoved therefrom, much greater economies are realized as compared withThus, in such a reloadingoperation effected with the aid of the improvedmechanism'described, only two men will be required as the lifttruck .canplace the palletwhere itis-wanted without handling. The pallets are'loadedwithin the warehouse ormill and the lift truck transports a loadto the carand deposits it in the car, successive loads being placed oneupon the other by the. truck. to the limit permitted by the height ofthe roof, without, as previously explained, any handling. Indeterminingthenumber. of bags to-be incorporated into each successive load.consideration must be given to the. distancethe machine .travels fromthe point ofv loading of the pallettothepoint of. discharge of the loadin the box car, the loads being preferably so made up that the menloading the pallets can always be ahead of the truck. This permits thetruck to travel continuously at its maximum speed so that the mosteconomical results are, in this respect, realized. Two men can, withoutundue exertion, load pallets slightly faster than the truck can removethem, the operation being so planned and, toward the end of the loadingmay have loaded several skids or platforms in excess of the numberwithdrawn by the truck. The men who have thus been actually loading thepallets within the warehouse may then move to the car and assist in themanual storage within the car of that portion of its loading which mustbe stacked by hand, i. e. the area adjacent the door of the car. Whenthree men are thus used to load a car the saving of labor, ascomparedwith the situation in which conventional pallets are used and involvingthe employment of five men, is approximately 40% and, in addition, thereare no empty pallets to handle so that the saving can and frequentlydoes amount to 50% over present methods employing conventional pallets.On the complete operation of unloading, storing and reloading a box carthere may thus be an overall labor saving over present methods, of 25%to 30% of the total actual labor costs and this is in addition to theadditional saving realized by dispensing with the use of a large numberof pallets.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. A load carrying pallet for a fork lift truck, adapted to be loaded,picked up and transported, said pallet comprising a rigid plate havingmeans aiiixed thereto for supporting one edge only so that the pallet,when placed upon a horizontal support, will be inclined, and a hookattached to the underside of the pallet adjacent the edge so elevatedand extending downwardly and inwardly, for the purpose set forth.

2. A load carrying pallet for a fork lift truck, adapted to be loaded,picked up and transported, said pallet comprising a rigid plate, and ahook attached to the underside of the plate extending downwardly andinwardly, for the purpose set forth.

3. In a combination of the class described, a lift truck having alifting platform with a detentengaging surface, said platform beingadapted to 10 a carry a load by application under the load, a thinsheet-like pallet adapted to be lifted by said lifting platform, lockingmeans extending downwardly from said pallet and coacting with saiddetent-engaging surface for locking said pallet against substantialsliding relatively to said lift-1 ing platform when resting in apredetermined position on said platform, said locking means including aportion for locking said pallet against tilting upwardly off saidlifting platform as when said pallet extends unsupported forwardlybeyond said lifting platform and a load is applied to said forwardlyextending portion.

4. In a combination of the class described, a lift truck having alifting platform adapted to carry a load by application under theload'and having a detent-engaging surface, a thin sheetlike palletadapted to be lifted by said lifting platform, means extendingdownwardly from said pallet and coacting with said detent-engagingsurface for locking said pallet against substantial sliding relativelyto said lifting platform when resting in a predetermined position onsaid platform, said means including a portion for locking said palletagainst tilting upwardly off said lifting platform as when said palletextends unsupported forwardly beyond said lifting platform and a load isapplied to said forwardly extending portion, andsaid means being sopositioned relatively to said pallet as to maintain said pallet with oneedge against the ground and the floor of the pallet angular to theground when the pallet rests on a flat piece of ground.

GEORGE BEVAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,524,473 Brinton Jan. 27, 19251,896,543 Gfrorer Feb. 7, 1933 1,934,289 White Nov. 7, 1933 2,256,454Bomar Sept. 16, 1941 2,302,137 Neuman Nov. 17, 1942 2,412,155 Jessen Q.Dec. 3, 1946 2,421,128 Pride May 27, 1947 2,441,750 Britton May 18, 19482,452,356 Goit, Jr Oct. 26, 1943 2,468,055 Gibler Apr. 26, 1949

